Alterations in enamel surface morphology after using six bleaching products - A scanning electron microscope study

The purpose of this study was to analyze the effect of six bleaching products on enamel surface morphology using scanning electron microscope (SEM). The crowns of eleven human premolars recently extracted were sectioned mesiodistally using water-cooled slow speed diamond saw. Twenty-one dental fragments were divided into seven groups as per treatment modality (n = 3): Opalescence Xtra for office bleaching (35% hydrogen peroxide), two professional home bleaching products: Nite White (16% carbamide peroxide) and Bleach 10 (10% carbamide peroxide), three over the counter bleaching systems: Rapid White gel, Rapid White 2 Steps Brush On (non peroxide bleaching products) and Natural White gel (hydrogen peroxide concentration is not indicated). The seventh group was stored in artificial saliva to serve as control. The bleaching procedures were conducted on enamel surfaces according to manufacturer’s instructions. The office bleaching procedure was conducted once weekly for two weeks and the other home bleaching procedures were conducted daily for two weeks. Following each bleaching session, the specimens were kept in artificial saliva. Control specimens were kept in artificial saliva for two weeks at 37 oC. After 2 weeks, the specimens were examinated for surface changes with scanning electron microscope. The SEM showed enamel surface alterations on all surfaces treated with all the bleaching agents used in this study. However, enamel surfaces treated with 35% hydrogen peroxide showed the most significant changes with increase in surface pores and big areas of surface destruction. Surface alterations caused by the other products were not uniform, occurring with varying intensity.